Drying process



Patented July 19, 1932 UNITED STATES PATENT OFFICE RICHARD ELSSNER, OFJOHNSON CITY, TENNESSEILASSIGNOR TO AMERICAN GLANZ- STOFF CORPORATION,OF NEW YORK, N. Y., A CORPORATION OF DELAWARE DRYING PROCESS No Drawing.

My present invention has to do with a new method for drying yarn onspools.

.' One object of this invention is to provide a spooled yarn with atechnically even shrinkage.

Other objects will become pparent'from a study of the following specication.

In the manufacture of artificial silk by the viscose process, thesolution is extruded through fine openings in a spinneretintoafixing orcoagulating bath. Here the filaments are hardened to a certain degree,and then wound upon some type of holder, vfor example, a foraminatedspool or bobbin. The yarn thus formed must be wet-treated in order tofree it from chemicals, and dried. It has been found that this dryingtends, ordinarily,

to cause an uneven shrinkage of the formed filaments. It is to overcomethis uneveness that I have devised my new process.

As one method of applying my new process, the following may beconsidered. The filaments are formed and collected on normal spools,which may or may not be perforated. After the customary wet-treatmcntthe spools containing the yarn are dried very slowly, for example, at atemperature of from 20 to 0., and an air humidity of from 60 to 80%. Nowrappings are employed on the filaments during this drying process.

The dried yarn is then twisted, from the spool in a loose body, uponanother spool.

This yarn is then rewet (by spraying or dipping, for example) and againdried very slowly as noted above.

As an example of my process, spool 200 mm. long holding viscose yarn of150 denier, 32

filaments (about 370 grams of yarn per spool) v is dried for a period ofapproximately 60 hours at a' temperature of from 20 to 30 C., and arelative humidity of about 50 to 70% until the moisture content is about10 to 18%.

. After twisting and rewettin in the manner outlined above, this type ofs ow drying is repeated. I No wrapping of any type 15 employed.

Although the description of my invention has been written with respectto the viscose filament-forming process above, it is to be understoodthat I do not desire to limit my Application filed September 11, 1931.Serial No. 562,427.

invention thereby. This process may also be used where other processesrequiring wetproximately 80% twisting into a loose body onto anotherholder, rewettingthe yarn, and redrying the same slowly.

2. In a process of the class described, the steps of spinning a viscosesolution directly onto spools, wet-treating the yarn thus spun, dryingslowly at a temperature of from 20 to 30 0., and at a humidity of 80% orover, rewinding in a loose bod onto another spool,

and then rewetting an redrying the yarn slowly.-

3. In a process for producing artificial yarn with a technically evenshrinkage, the steps of wet treating the filaments, drying them slowlyat approximately room temperature and in an atmosphere possessing ahumidity of or over, rewinding the yarn body so that the filamentsformerly on the outside are on the inside, rewetting the yarn, andredrying it.

4. A process as set forth in claim 3, where in the second drying is alsoat approximately room temperature and in an atmosphere of relativelyhigh humidity.

In testimony whereof I alfix my signature. DR. RICHARD ELSSNER.

